Trailers of tractor/trailer combinatinations have conventionally used landing gear, generally consisting of a pair of retractable legs, at the front ends of the trailers to support such front ends when the tractor is to be detached from the trailer. FIG. 1 depicts a conventional landing gear assembly 10. As can be seen in the view of FIG. 1, the landing gear 10 has a driven shaft 12 which passes through the upper ends of a pair of telescoping legs 14. Each leg 14 has an outer rectangular body 16 in which an inner rectangular portion 18 is telescopically received. Conventional gear mechanisms (not shown) cause the inner rectangular portion 18 to raise or lower, depending upon the direction of rotation of the driven shaft 12. A gear reduction box 20 is conventionally provided as depicted in FIG. 1. The gear reduction box will generally provide two gear ratios, which are generally 1/1 (meaning one inch of lift per rotation of a driving shaft 22) or 40/1 (meaning one inch of lift per forty rotations of the driving shaft 22). On the prior art conventional devices, a crank handle 24 is affixed to the driving shaft 22 by a removable pin 26. Accordingly, rotation of the crank handle 24 will selectively raise or lower the legs 14 of the landing gear 10.
As can be appreciated, raising and lowering the landing gear 10 using the manual crank handle 24 is both laborious and time consuming. A number of devices have been devised for raising and lowering the landing gear 10 by powered devices. Most of these have been hydraulically powered, although other power means have been used for the purpose. However, the fact that the old fashioned hand crank still predominates in the field speaks to the fact that known devices are, for one reason or another impractical.
The copending U.S. patent Application Ser. No. 09/075,494, having an inventor in common with this present application, has taught a pneumatic and/or electrical device for raising and lowering the landing gear 10. While this invention has achieved its goals admirably, it is accepted that a simpler, or less expensive, or more reliable alternative is generally desirable. Indeed, it is often the simpler alternatives which are less obvious, becoming understood only after experience with earlier, more cumbersome, devices is accrued. Accordingly, although the device taught by the '494 Application has provided an improvement over the manual method, which has been the standard mode of operation for many years, there remains the desirability to provide an even more effective alternative.